Bathurst, Bluenose-East caribou herds still declining: initial report
Proportion of breeding cows has dropped, according to preliminary data from a June survey of calving grounds
The Bathurst and Bluenose-East caribou herds in the Northwest Territories are continuing to decline in numbers, according to preliminary results from this summer's calving ground survey.
"Preliminary findings suggest further decreases in both herds compared to the 2012 (Bathurst) and 2013 (Bluenose-East) calving ground photo surveys," reads an initial report sent by the N.W.T. Department of Environment and Natural Resources to N.W.T. First Nations, Nunavut government representatives and renewable resource boards in July.
The 2012 survey of the Bathurst herd estimated the population at 35,000 animals, down from 186,000 in 2003.
The 2013 survey of the Bluenose-East herd, which ranges from Colville Lake to the Beaufort Sea, found it had declined to about 68,000 animals, down from more than 100,000 in 2010.
The report says the proportion of breeding cows seen in the survey was 59 per cent, down from 68 per cent in 2012, suggesting lower pregnancy rates and calving rates.
It says the continuing declines mean management actions will need to continue, and that discussions would need to begin this summer on how to deal with the declines.
In January, the N.W.T. government established a mobile no-hunting zone around the core of the Bathurst caribou herd where hunting is banned. It also limited the number of bulls outside of the no-hunting zone allowed to be taken for ceremonial purposes.
Hunting of the Bluenose-East caribou herd is limited to 1,800 animals, 80 per cent of which must be bulls.
Dr. Justina Ray, president and senior scientist at WCS Canada and co-author of Caribou and the North: A Shared Future, says that while it's clear the herds are declining, biologists aren't sure why.
"The reasons for these declines are not understood, and complicated by the fact that these caribou herds have been known to experience fluctuations; in other words, they have declined and increased again in the past," she told CBC News in an email.
"However, some conditions on the ranges of these herds have changed in relatively recent times – namely land use changes (development pressures) and climate change, and combined with hunting, may in certain cases either accelerate declines or leave conditions unfavourable for natural recovery."
Analysis of the surveys is still in progress and final population estimates are expected to be released for the Bathurst herd by late September, and for the Bluenose-East herd by early November.
The photo surveys of the calving grounds were done in June by representatives from ENR, along with members of the Yellowknives Dene First Nation, the Tlicho Government and the N.W.T. Metis Nation.
The report says the survey "was done at the peak of calving, and good weather and visibility ensured the collection of very good field data and photographs.
"As a result, we can expect a high level of confidence in the final survey results once they are available."